Qualcomm Technologies, Inc. MDSS pll for DSI/EDP/HDMI

mdss-pll is a pll controller device which supports pll devices that
are compatible with MIPI display serial interface specification,
HDMI and edp.

Required properties:
- compatible:		Compatible name used in the driver. Should be one of:
                        "qcom,mdss_dsi_pll_8916", "qcom,mdss_dsi_pll_8939",
                        "qcom,mdss_dsi_pll_8974", "qcom,mdss_dsi_pll_8994",
                        "qcom,mdss_dsi_pll_8994", "qcom,mdss_dsi_pll_8909",
                        "qcom,mdss_hdmi_pll", "qcom,mdss_hdmi_pll_8994",
                        "qcom,mdss_dsi_pll_8992", "qcom,mdss_hdmi_pll_8992",
                        "qcom,mdss_dsi_pll_8996", "qcom,mdss_hdmi_pll_8996",
                        "qcom,mdss_hdmi_pll_8996_v2", "qcom,mdss_dsi_pll_8996_v2",
                        "qcom,mdss_hdmi_pll_8996_v3", "qcom,mdss_hdmi_pll_8996_v3_1p8",
                        "qcom,mdss_edp_pll_8996_v3",  "qcom,mdss_edp_pll_8996_v3_1p8",
                        "qcom,mdss_dsi_pll_10nm",  "qcom,mdss_dp_pll_8998",
                        "qcom,mdss_hdmi_pll_8998", "qcom,mdss_dp_pll_10nm",
                        "qcom,mdss_dsi_pll_7nm",   "qcom,mdss_dp_pll_7nm",
			"qcom,mdss_dsi_pll_28lpm", "qcom,mdss_dsi_pll_14nm",
			"qcom,mdss_dp_pll_14nm", "qcom,mdss_dsi_pll_7nm_v2",
			"qcom,mdss_hdmi_pll_28lpm","qcom,mdss_dsi_pll_7nm_v4_1",
			"qcom,mdss_dp_pll_7nm_v2"
- cell-index:		Specifies the controller used
- reg:			offset and length of the register set for the device.
- reg-names :		names to refer to register sets related to this device
- gdsc-supply:		Phandle for gdsc regulator device node.
- vddio-supply:		Phandle for vddio regulator device node.
- clocks:		List of Phandles for clock device nodes
			needed by the device.
- clock-names:		List of clock names needed by the device.
- clock-rate:		List of clock rates in Hz.

Optional properties:
- label:	       	A string used to describe the driver used.
- vcca-supply:		Phandle for vcca regulator device node.


- qcom,dsi-pll-ssc-en:	Boolean property to indicate that ssc is enabled.
- qcom,dsi-pll-ssc-mode: Spread-spectrum clocking. It can be either "down-spread"
			or "center-spread". Default is "down-spread" if it is not specified.
- qcom,ssc-frequency-hz:	Integer property to specify the spread frequency
			to be programmed for the SSC.
- qcom,ssc-ppm:		Integer property to specify the Parts per Million
			value of SSC.

- qcom,platform-supply-entries:	A node that lists the elements of the supply. There
				can be more than one instance of this binding,
				in which case the entry would be appended with
				the supply entry index.
				e.g. qcom,platform-supply-entry@0
				- reg: offset and length of the register set for the device.
				-- qcom,supply-name: name of the supply (vdd/vdda/vddio)
				-- qcom,supply-min-voltage: minimum voltage level (uV)
				-- qcom,supply-max-voltage: maximum voltage level (uV)
				-- qcom,supply-enable-load: load drawn (uA) from enabled supply
				-- qcom,supply-disable-load: load drawn (uA) from disabled supply
				-- qcom,supply-pre-on-sleep: time to sleep (ms) before turning on
				-- qcom,supply-post-on-sleep: time to sleep (ms) after turning on
				-- qcom,supply-pre-off-sleep: time to sleep (ms) before turning off
				-- qcom,supply-post-off-sleep: time to sleep (ms) after turning off

Example:
	mdss_dsi0_pll: qcom,mdss_dsi_pll@fd922A00 {
		compatible = "qcom,mdss_dsi_pll_8974";
		label = "MDSS DSI 0 PLL";
		cell-index = <0>;

		reg = <0xfd922A00 0xD4>,
		      <0xfd922900 0x64>,
		      <0xfd8c2300 0x8>;
		reg-names = "pll_base", "dynamic_pll_base", "gdsc_base";
		gdsc-supply = <&gdsc_mdss>;
		vddio-supply = <&pm8941_l12>;
		vcca-supply = <&pm8941_l28>;

		clocks = <&clock_gcc clk_gcc_mdss_mdp_clk>,
			 <&clock_gcc clk_gcc_mdss_ahb_clk>,
			 <&clock_gcc clk_gcc_mdss_axi_clk>;
		clock-names = "mdp_core_clk", "iface_clk", "bus_clk";
		clock-rate = <0>, <0>, <0>;

		qcom,dsi-pll-slave;
		qcom,dsi-pll-ssc-en;
		qcom,dsi-pll-ssc-mode = "down-spread";
		qcom,ssc-frequency-hz = <30000>;
		qcom,ssc-ppm = <5000>;

		qcom,platform-supply-entries {
			#address-cells = <1>;
			#size-cells = <0>;

			qcom,platform-supply-entry@0 {
				reg = <0>;
				qcom,supply-name = "vddio";
				qcom,supply-min-voltage = <1800000>;
				qcom,supply-max-voltage = <1800000>;
				qcom,supply-enable-load = <100000>;
				qcom,supply-disable-load = <100>;
				qcom,supply-pre-on-sleep = <0>;
				qcom,supply-post-on-sleep = <20>;
				qcom,supply-pre-off-sleep = <0>;
				qcom,supply-post-off-sleep = <0>;
			};
		};
	};

